protobuf-net v2 是否需要 DataMember(Order=n) 注释? [英] Is DataMember(Order=n) annotation required for protobuf-net v2?

问题描述

简单实验:我从 Northwind 创建了一个实体模型，发现生成的类在不添加 Order 属性的情况下不适用于 protobuf-net v2.有没有办法让实体代码生成器添加Order，或者有没有办法让protobuf-net在没有Order的情况下工作?

Simple experiment: I created an entity model from Northwind, and find that the generated classes don't work for protobuf-net v2 without adding the Order property. Is there a way to get the entity code generator to add Order, or is there a way to get protobuf-net to work without Order?

我必须改变

[DataMemberAttribute()]

到

[DataMemberAttribute(Order=1)] 等

NorthwindEntities e = new NorthwindEntities();

using(var file = File.Create("customers.bin"))
{
    Serializer.Serialize(file, e.Customers);
}

推荐答案

要求是它有一种方法可以将成员解析为数字键.这个可以采用内联属性的形式——例如，它允许 [DataContract]/[DataMember(Order=key)], [XmlType]/[XmlElement(Order=key)] 或 [ProtoContract]/[ProtoMember(key)].

What is required is that it has a way to resolve members to numeric keys. This can take the form of inline attributes - for example, it allows [DataContract]/[DataMember(Order=key)], [XmlType]/[XmlElement(Order=key)], or [ProtoContract]/[ProtoMember(key)].

还可以通过 [DataContract] 选择按字母顺序推断合同，但这只有在您的合同类型不会改变时才安全强>在未来；为此，请添加:

There are also options via [DataContract] to infer the contract alphabetically, but this is only safe if your contract type is not going to change in the future; to do this, add:

[ProtoContract(InferTagFromName = true)]

到类型(也许是部分的，见下文).这直接适用于您呈现的场景，其中[DataMember] 表示成员，但没有定义Order.为了稳定性，我个人更喜欢显式布局.

to the type (perhaps in a partial, see below). This applies directly to the scenario you present, where [DataMember] indicates the members, but there is no defined Order. Personally I prefer explicit layouts, for stability.

另一个选项甚至不需要像 [DataMember] 这样的提示；您可以要求它应用 BinaryFormatter 规则(所有字段，公共或私有)或 XmlSerializer 规则(公共成员、属性或字段)；不过，如果您的类型发生变化，这会非常不稳定！

Another option doesn't even need hints like [DataMember]; you can ask it to apply either BinaryFormatter rules (all fields, public or private), or XmlSerializer rules (public members, properties or fields); again, though, this is very unstable if your type changes!

[ProtoContract(ImplicitFields = ImplicitFields.AllPublic)]

但是；另一个常见的情况是您的类型来自生成器，您无法方便地对其进行编辑，因为任何编辑都会在重新生成时丢失；对于那个场景，partial 类可能会有所帮助.您不能通过属性向成员添加属性，但是 [ProtoPartialMember] 可以在这里提供帮助.例如，在单独的代码文件中:

But; another common scenario is that you have types coming from a generator, that you can't conveniently edit, since any edits would get lost at re-generation; for that scenario, partial classes can be helpful. You can't add attributes to members via attributes, but [ProtoPartialMember] can help here. For example, in a separate code file:

[ProtoContract]
[ProtoPartialMember(key, memberName)]
[ProtoPartialMember(anotherKey, anotherMemberName)]
...
public partial class Order {}

有时，您无权访问任何类型，因此添加任何类型的属性都不是一种选择.如果您的场景如您所描述的([DataContract/[DataMember], noOrder`)，则 lazy 选项是全局启用此功能:

Sometimes, you have no access whatsoever to the type, so adding attributes of any kind is not an option. If your scenario is as you describe ([DataContract/[DataMember], noOrder`), then a lazy option is to enable this globally:

Serializer.GlobalOptions.InferTagFromName = true;

或在 v2 中:

RuntimeTypeModel.Default.InferTagFromNameDefault = true;

对于更复杂的场景，v2 有一个新的 MetaType 模型专门用于此，您可以在运行时配置布局:

For more complex scenarios, v2 has a new MetaType model devoted to this, where you can configure the layout at runtime:

RuntimeTypeModel.Default.Add(typeof(Order), false)
            .Add(key, memberName).Add(anotherKey, anotherMemberName);

或者如果你的键是 1, 2, 3, ... 那么就:

or if your keys are 1, 2, 3, ... then just:

   RuntimeTypeModel.Default.Add(typeof(Order), false)
            .Add(memberName, anotherMemberName, ...);

(MetaType 上有无数的选项来控制序列化的所有方面)

(there are a myriad of options on the MetaType to control all aspects of the serialization)

我认为涵盖了这里的大部分选项！

I think that covers most of the options here!

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